Kicx QS-300 (4+4)

12″ subwoofer · dual 4 Ω · 700 W RMS

Fs 27 HzQts 0.51Vas 2.05 ft³Xmax 0.56″

Recommended box

For a sedan, one sub, 700 W. It’s the same math as the designer’s step-by-step mode, where you can fit the box to your space, vehicle and amp and get plans, a cut sheet and DXF.

Sealed

Net volume1.34 ft³ (38 L)
Qtc0.80
Fc43 Hz
F3 (−3 dB, no cabin gain)40 Hz
Example box (outside)14 3/16″ × 14 3/16″ × 16 13/16″
Open sealed box in designer

Ported

Net volume2.93 ft³ (83 L)
Tuning (Fb)27 Hz
Portslot 2 3/8 × 14 5/16″, 37 9/16″ long
Port velocity at 700 W60 ft/s
F3 (−3 dB, no cabin gain)25 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 17 1/4″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs27 Hz
Qts0.51
Qes0.581
Qms3.87
Vas2.05 ft³
Re (one coil)≈ 3.4 Ω
Sd≈ 76 in²
Xmax0.56″
EBP46 — suits sealed calc.
Sensitivity, 1 W / 1 m84.9 dB calc.

General

Size12″
Voice coilsdual 4 Ω
RMS power700 W

Mounting dimensions

Ø≈ 12 5/16″cutout ≈ Ø11 1/8″mounting depth 7 7/8″magnet Ø≈ 7 3/16″
Cutout diameter≈ 11 1/8″
Mounting depth7 7/8″

“≈” means the value isn’t in the spec sheet and a typical value for the size is used; “calc.” means it’s calculated from the published parameters. Check the manufacturer’s spec sheet before you build.

Data sources

Other Kicx 12″ models